Data under voice communications system
AssigneeApplied Spectrum Technologies, Inc.
InventorsDonald W. Moses, Charles Hustig, C. Ray Ballard
Life of this patent
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Abstract
A communications system capable of simultaneously transmitting voice and data information. The spectral energy of the data signal is smeared by spreading it in a spectrum with energy packed in the lower frequency range under the conventional voice signal frequency in a manner which complements the standard C-message weighting curve. The use of the spread spectrum technique also eliminates thumping at the data rate since the harmonics that produce thumping are also spread throughout the bandwidth.
Claims40
A communications system for communicating data information simultaneously with voice transmission at frequencies less than the voice transmission comprising:
- means for generating at least one digital data signal;
- means for generating at least one spreading frequency;
- means for combining the data signal and the spreading frequency to create a spreading code for transmission of the data which causes the data to be transmitted at three or more fundamental frequencies;
- and
- means for transmitting the fundamental frequencies simultaneously with the voice transmission, the data being transmitted as a coherent frequency modulated signal having a constantly varying fundamental frequency less than the voice frequency bandwidth.
A method for communicating data information over a communications medium at frequencies less than voice transmission frequencies comprising:
- generating at least one digital data signal;
- generating at least one spreading frequency;
- combining the data signal and spreading frequency to create a spreading code for transmission of the data which causes the data to be transmitted at three or more fundamental frequencies;
- and
- transmitting the fundamental frequencies as a coherent frequency modulated signal having a constantly varying fundamental frequency less than the voice frequency bandwidth.
Dependencies are inferred from the claim text.